chad

module Foo
  def self.included(klass)
    klass.extend ClassMethods
  end
  module ClassMethods
    def foo(name)
      (class << self; self; end).send :attr_accessor, name
    end
  end
end

chad

class Class
  def attr_with_default(attr_name, default_value)
    attr_writer attr_name
    define_method(attr_name) do
      instance_variable_get("@#{attr_name}") || default_value
    end
  end
end

class Person

chad

require 'csv'

module Exporter
  DEFAULT_EXPORT_TABLES = [ Invoice, InvoiceItem, Item, Merchant, Transaction, User ]
  DESTINATION_FOLDER = "tmp/"

  def self.included(klass)
    klass.extend ClassLevelMethods
  end

chad

def add(key, value, dictionary = Proc.new{})
  lambda do |x|
    key == x ? value : dictionary.call(x)
  end
end

d = add("a",5)
d = add("b",6, d)

p d.call("b")

chad

for file in app/**/*rb; do 
  echo -n $file, " . "; git --no-pager log --pretty="format:%ai" -1 $file; echo; 
done

chad

def assert_difference(string, expected_difference = 1, &block)
  before = eval(string, block.binding)
  block.call
  after = eval(string, block.binding)
  fail "Expected a difference of #{expected_difference}" unless after - before == expected_difference
end

a = 1
assert_difference("a", 1) do
  a += 1

chad

def create_multipler(factor)
  ->param{param * factor}
end

times_2 = create_multipler(2)
p times_2.(4)
exit
class Foo
  1_000_000_000.times do |n|
    define_method("times_#{n}") do |param|

chad

Around methods:
method_missing, method_added, singleton_method_added, method_removed, singleton_method_removed, method_undefined, singleton_method_undefined
Around classes and modules
inherited, append_features, included, extend_object, extended, initialize_copy, const_missing
Marshaling
marshal_dump, marshal_load
Numbers
coerce, induced_from

chad

configuration = configure do |config|  
  config.tail_logs = true  
  config.max_connections = 55  
  config.admin_password = 'secret'  
  config.app_server do |app_server_config|  
    app_server_config.port = 8808  
    app_server_config.admin_password = config.admin_password  
  end  
end  
  

chad

#hello